Catalyzed deposition of metal films

ABSTRACT

Methods of depositing a metal film with high purity are discussed. Some embodiments utilize a thermal ALD process comprising an alkyl halide and a metal precursor. Some embodiments selectively deposit a metal film with high purity on a metal surface over a dielectric surface. Some embodiments selectively deposit a metal film with high purity on a dielectric surface over a metal surface. Some embodiments deposit a metal film with greater than 99% metal atoms on an atomic basis.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No.62/688,758, filed Jun. 22, 2018, U.S. Provisional Application No.62/808,268, filed Feb. 20, 2019, U.S. Provisional Application No.62/830,909, filed Apr. 8, 2019, U.S. Provisional Application No.62/830,911, filed Apr. 8, 2019, and U.S. Provisional Application No.62/849,011, filed May 16, 2019, the entire disclosures of which arehereby incorporated by reference herein.

FIELD

Embodiments of the disclosure generally relate to methods for depositingmetal films. Some embodiments of the disclosure are directed to methodsfor depositing metal films. Some embodiments of the disclosure relate tothe selective deposition of metal films. Some embodiments of thedisclosure control the location and/or rate of deposition through theuse of plasma and/or thermal exposure conditions.

BACKGROUND

The semiconductor industry continues to strive for continuous deviceminiaturization that is driven by the need for mobile andhigh-performance systems in emerging industries such as autonomousvehicles, virtual reality, and future mobile devices. To accomplish thisfeat, new, high-performance materials are needed to circumvent inherentengineering, chemical and physics issues encountered in the rapidreduction of features in microelectronic devices.

Ruthenium is a new proposed material for integration owing to its highmelting point (ability to withstand high current densities), exceptionaldensity, and ability to conduct electrical current. Ruthenium andruthenium containing thin films have attractive material and conductiveproperties. Ruthenium films have been proposed for applications rangingfrom front end to back end parts of semiconductor and microelectronicdevices.

Thin-films of ruthenium would ideally be deposited using thin-filmdeposition techniques such as Chemical Vapor Deposition (CVD) and AtomicLayer Deposition (ALD) owing to their inherent ability to depositmaterial in a high-throughput and precise fashion.

Yet deposited ruthenium films often differ from bulk rutheniummaterials. There is particular challenge in depositing ruthenium filmswith high purity (>99 atomic % of Ru), especially as gap fill material.Previous solutions utilizing oxygen reactants produced films withgreater roughness than bulk materials. Similarly, hydrogen reactantsproduced greater impurities which required a subsequent annealing stepfor removal. Finally, plasma deposition processes were unable to depositgap fill materials without creating a seam and potentially damaging theunderlying substrate.

Therefore there is a need for methods and materials for depositing highpurity conformal ruthenium films as gap fil. There is also a need formethods and materials for depositing ruthenium films as gapfill withoutseams or voids.

Additionally, as the design of semiconductor devices evolve, precisionmaterial manufacturing in the semiconductor industry has entered an eraof atomic scale dimensions. At the atomic scale, with only tens of atomsat stake, there is little margin for error. This unprecedented challengedemands new material processing techniques which have atomic levelprecision. However, increasing the complexity of the process flowrequired in atomic scale device manufacturing can significantly lowerthroughput and increase the cost of manufacturing.

Selective deposition technologies offer the potential forchemically-selective atomic-layer precision in semiconductor filmpatterning. Selective deposition also offers the potential for simplerprocess flows by eliminating lithography or other processes.

Selective deposition of materials can be accomplished in a variety ofways. For instance, some processes may have inherent selectivity tosurfaces based on their surface chemistry. These processes are fairlyrare and usually need to have surfaces with drastically differentsurface energies, such as metals and dielectrics.

Therefore there is a need for methods of selectively depositing metalfilms on metallic surfaces over dielectric surfaces, or vice versa.

Further, current devices use tungsten films for memory and logicapplications. Deposition of tungsten films is frequently performed atrelatively high temperatures which can be limited by the thermal budgetof the device being formed. Tungsten films are often deposited usingfluorine containing compounds. Fluorine is generally not desirable inthe deposition process as there can be reactions and adverse effects. Toprevent fluorine from reacting with the underlying layers, a relativelythick barrier layer is used. The barrier layer deposition decreasesthermal budget and throughput.

Therefore there is a need in the art for conductive materials that donot use fluorine and/or can be deposited at low temperatures.

SUMMARY

One or more embodiments of the disclosure are directed to a metaldeposition method. A substrate is sequentially exposed to a metalprecursor and an alkyl halide to form a metal film. The substrate ismaintained at a deposition temperature. The metal precursor has adecomposition temperature above the deposition temperature. The alkylhalide comprises carbon and halogen. The halogen comprises bromine oriodine.

Additional embodiments of the disclosure are directed to a method ofselectively depositing a first metal film on a first dielectric surface.The method comprises providing a substrate with a first dielectricsurface and a second metal surface. The substrate is exposed to ablocking compound to block the second metal surface. The blockingcompound has the general formula of R′≡R″, where R′ and R″ are an alkylor other carbonaceous group. The substrate is sequentially exposed to afirst metal precursor and an alkyl halide while the substrate ismaintained at a deposition temperature. The alkyl halide comprisescarbon and halogen atoms. The halogen atoms comprise bromine or iodine,and the deposition temperature is between the decomposition temperatureof the alkyl halide and the first metal precursor.

Further embodiments of the disclosure are directed to a method ofselectively depositing a first metal film on a second metal surface. Themethod comprises providing a substrate with a first dielectric surfaceand a second metal surface. The substrate is sequentially exposed to afirst metal precursor and an alkyl halide while the substrate ismaintained at a deposition temperature. The alkyl halide comprisescarbon and halogen atoms. The halogen atoms comprise bromine or iodine.Both the metal precursor and the alkyl halide have a decompositiontemperature above the deposition temperature.

BRIEF DESCRIPTION OF THE DRAWING

So that the manner in which the above recited features of the presentdisclosure can be understood in detail, a more particular description ofthe disclosure, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this disclosure and are therefore not to beconsidered limiting of its scope, for the disclosure may admit to otherequally effective embodiments.

FIG. 1 shows a schematic view of a processing platform in accordancewith one or more embodiment of the disclosure;

FIG. 2 shows a cross-sectional view of a batch processing chamber inaccordance with one or more embodiment of the disclosure;

FIG. 3 shows a partial perspective view of a batch processing chamber inaccordance with one or more embodiment of the disclosure;

FIG. 4 shows a schematic view of a batch processing chamber inaccordance with one or more embodiment of the disclosure;

FIG. 5 shows a schematic view of a portion of a wedge shaped gasdistribution assembly for use in a batch processing chamber inaccordance with one or more embodiment of the disclosure;

FIG. 6 shows a schematic view of a batch processing chamber inaccordance with one or more embodiment of the disclosure;

FIG. 7 illustrates an exemplary process sequence for the formation of ametal layer using a two pulse cyclical deposition technique according toone or more embodiment of the disclosure;

FIG. 8 illustrates an exemplary process sequence for the formation of aruthenium layer according to one or more embodiment of the disclosure;

FIG. 9 shows a cross-sectional view of an exemplary substrate inaccordance with one or more embodiment of the disclosure; and

FIGS. 10A-10D illustrate an exemplary substrate during processingaccording to one or more embodiment of the disclosure.

In the appended figures, similar components and/or features may have thesame reference label. Further, various components of the same type maybe distinguished by following the reference label by a dash and a secondlabel that distinguishes among the similar components. If only the firstreference label is used in the specification, the description isapplicable to any one of the similar components having the same firstreference label irrespective of the second reference label.

DETAILED DESCRIPTION

Before describing several exemplary embodiments of the disclosure, it isto be understood that the disclosure is not limited to the details ofconstruction or process routines set forth in the following description.The disclosure is capable of other embodiments and of being practiced orbeing carried out in various ways.

A “substrate”, “substrate surface”, or the like, as used herein, refersto any substrate or material surface formed on a substrate upon whichprocessing is performed. For example, a substrate surface on whichprocessing can be performed include, but are not limited to, materialssuch as silicon, silicon oxide, strained silicon, silicon on insulator(SOI), carbon doped silicon oxides, silicon nitride, doped silicon,germanium, gallium arsenide, glass, sapphire, and any other materialssuch as metals, metal nitrides, metal alloys, and other conductivematerials, depending on the application. Substrates include, withoutlimitation, semiconductor wafers. Substrates may be exposed to apretreatment process to polish, etch, reduce, oxidize, hydroxylate (orotherwise generate or graft target chemical moieties to impart chemicalfunctionality), anneal and/or bake the substrate surface. In addition toprocessing directly on the surface of the substrate itself, in thepresent disclosure, any of the film processing steps disclosed may alsobe performed on an underlayer formed on the substrate as disclosed inmore detail below, and the term “substrate surface” is intended toinclude such underlayer as the context indicates. Thus for example,where a film/layer or partial film/layer has been deposited onto asubstrate surface, the exposed surface of the newly deposited film/layerbecomes the substrate surface. What a given substrate surface compriseswill depend on what materials are to be deposited, as well as theparticular chemistry used.

“Atomic layer deposition” or “cyclical deposition” as used herein refersto the sequential exposure of two or more reactive compounds to deposita layer of material on a substrate surface. As used in thisspecification and the appended claims, the terms “reactive compound”,“reactive gas”, “reactive species”, “precursor”, “process gas” and thelike are used interchangeably to mean a substance with a species capableof reacting with the substrate surface or material on the substratesurface in a surface reaction (e.g., chemisorption, oxidation,reduction). The substrate, or portion of the substrate, is exposedseparately to the two or more reactive compounds which are introducedinto a reaction zone of a processing chamber. In a time-domain ALDprocess, exposure to each reactive compound is separated by a time delayto allow each compound to adhere and/or react on the substrate surfaceand then be purged from the processing chamber. These reactive compoundsare said to be exposed to the substrate sequentially. In a spatial ALDprocess, different portions of the substrate surface, or material on thesubstrate surface, are exposed simultaneously to the two or morereactive compounds so that any given point on the substrate issubstantially not exposed to more than one reactive compoundsimultaneously. As used in this specification and the appended claims,the term “substantially” used in this respect means, as will beunderstood by those skilled in the art, that there is the possibilitythat a small portion of the substrate may be exposed to multiplereactive gases simultaneously due to diffusion, and that thesimultaneous exposure is unintended.

In one aspect of a time-domain ALD process, a first reactive gas (i.e.,a first precursor or compound A) is pulsed into the reaction zonefollowed by a first time delay. Next, a second precursor or compound Bis pulsed into the reaction zone followed by a second delay. During eachtime delay, a purge gas, such as argon, is introduced into theprocessing chamber to purge the reaction zone or otherwise remove anyresidual reactive compound or reaction by-products from the reactionzone. Alternatively, the purge gas may flow continuously throughout thedeposition process so that only the purge gas flows during the timedelay between pulses of reactive compounds. The reactive compounds arealternatively pulsed until a desired film or film thickness is formed onthe substrate surface. In either scenario, the ALD process of pulsingcompound A, purge gas, compound B and purge gas is a cycle. A cycle canstart with either compound A or compound B and continue the respectiveorder of the cycle until achieving a film with the predeterminedthickness.

In an embodiment of a spatial ALD process, a first reactive gas andsecond reactive gas (e.g., metal precursor gas) are deliveredsimultaneously to the reaction zone but are separated by an inert gascurtain and/or a vacuum curtain. The substrate is moved relative to thegas delivery apparatus so that any given point on the substrate isexposed to the first reactive gas and the second reactive gas.

As used in this specification and the appended claims, the terms“precursor”, “reactant”, “reactive gas” and the like are usedinterchangeably to refer to any gaseous species that can react with thesubstrate surface.

Some embodiments of the disclosure are directed to processes that use areaction chamber with multiple gas ports that can be used forintroduction of different chemicals or plasma gases. Spatially, thesegas ports (also referred to as channels) are separated by inert purginggases and/or vacuum pumping holes to create a gas curtain that minimizesor eliminates mixing of gases from different gas ports to avoid unwantedgas phase reactions. Wafers moving through these different spatiallyseparated ports get sequential and multiple surface exposures todifferent chemical or plasma environment so that layer by layer filmgrowth in spatial ALD mode or surface etching process occur. In someembodiments, the processing chamber has modular architectures on gasdistribution components and each modular component has independentparameter control (e.g., RF or gas flow) to provide flexibility tocontrol, for example, gas flow and/or RF exposure.

Some embodiments of the disclosure provide methods for depositing a highpurity metal film. The methods of various embodiments use atomic layerdeposition (ALD) to provide pure or nearly pure metal films. Whileexemplary embodiments of this disclosure refer to the deposition ofruthenium, it is conceived that the principles of this disclosure enablethe deposition of highly pure metal films regardless of metal.

Some embodiments of the disclosure provide methods of selectivelydepositing metal films on a metal surface over a dielectric surface.Some embodiments of the disclosure provide methods of selectivelydepositing metal films on a dielectric surface over a metal surface. Asused in this specification and the appended claims, the term“selectively depositing a film on one surface over another surface”, andthe like, means that a first amount of the film is deposited on thefirst surface and a second amount of film is deposited on the secondsurface, where the second amount of film is less than the first amountof film, or no film is deposited on the second surface.

The term “over” used in this regard does not imply a physicalorientation of one surface on top of another surface, rather arelationship of the thermodynamic or kinetic properties of the chemicalreaction with one surface relative to the other surface. For example,selectively depositing a metal film onto a metal surface over adielectric surface means that the metal film deposits on the metalsurface and less or no metal film deposits on the dielectric surface; orthat the formation of a metal film on the metal surface isthermodynamically or kinetically favorable relative to the formation ofa metal film on the dielectric surface.

The selectivity of a deposition process is generally expressed as amultiple of growth rate. For example, if one surface is grown (ordeposited on) 25 times faster than a different surface, the processwould be described as having a selectivity of 25:1. In this regard,higher ratios indicate more selective processes.

Some embodiments of the disclosure advantageously provide methods fordepositing metal films with high purity. Accordingly, these highly purefilms exhibit similar properties to their associated bulk metallicmaterials. For example, some embodiments of this disclosure provideruthenium films which are smoother and have lower resistance thanruthenium films deposited by conventional oxygen or hydrogen reactantprocesses. Some embodiments of this disclosure advantageously providemetal films which conformally fill gaps without a seam.

Some embodiments of the disclosure advantageously provide for theselective deposition of metal films with high purity on metallicsurfaces over dielectric surfaces. For example, selectively depositingmetal (e.g., ruthenium) on copper over dielectrics advantageouslyprovides copper capping layers without additional etch or lithographysteps. Additionally, selective deposition may also enable bottom-upgapfill for trenches with metal contacts at the bottom and dielectricsidewalls.

Some embodiments of the disclosure advantageously provide for theselective deposition of metal films with high purity on dielectricsurfaces over metallic surfaces. For example, selectively depositingmetals over dielectrics advantageously provides metal layers on barriersor other dielectrics in back end applications.

Some embodiments of the disclosure utilize a spatial ALD process whichis performed on a processing platform as disclosed herein. Referring tothe Figures, FIG. 1 shows a processing platform 100 in accordance withone or more embodiment of the disclosure. The embodiment shown in FIG. 1is merely representative of one possible configuration and should not betaken as limiting the scope of the disclosure. For example, in someembodiments, the processing platform 100 has different numbers ofprocess chambers, buffer chambers and robot configurations.

The processing platform 100 includes a central transfer station 110which has a plurality of sides 111, 112, 113, 114, 115, 116. The centraltransfer station 110 shown has a first side 111, a second side 112, athird side 113, a fourth side 114, a fifth side 115 and a sixth side116. Although six sides are shown, those skilled in the art willunderstand that there can be any suitable number of sides to the centraltransfer station 110 depending on, for example, the overallconfiguration of the processing platform 100.

The transfer station 110 has a robot 117 positioned therein. The robot117 can be any suitable robot capable of moving a wafer duringprocessing. In some embodiments, the robot 117 has a first arm 118 and asecond arm 119. The first arm 118 and second arm 119 can be movedindependently of the other arm. The first arm 118 and second arm 119 canmove in the x-y plane and/or along the z-axis. In some embodiments, therobot 117 includes a third arm or a fourth arm (not shown). Each of thearms can move independently of other arms.

A first batch processing chamber 120 can be connected to a first side111 of the central transfer station 110. The first batch processingchamber 120 can be configured to process x wafers at a time for a batchtime. In some embodiments, the first batch processing chamber 120 can beconfigured to process in the range of about four (x=4) to about 12(x=12) wafers at the same time. In some embodiments, the first batchprocessing chamber 120 is configured to process six (x=6) wafers at thesame time. As will be understood by the skilled artisan, while the firstbatch processing chamber 120 can process multiple wafers betweenloading/unloading of an individual wafer, each wafer may be subjected todifferent process conditions at any given time. For example, a spatialatomic layer deposition chamber, like that shown in FIGS. 2 through 6,expose the wafers to different process conditions in differentprocessing regions so that as a wafer is moved through each of theregions, the process is completed.

FIG. 2 shows a cross-section of a processing chamber 200 including a gasdistribution assembly 220, also referred to as injectors or an injectorassembly, and a susceptor assembly 240. The gas distribution assembly220 is any type of gas delivery device used in a processing chamber. Thegas distribution assembly 220 includes a front surface 221 which facesthe susceptor assembly 240. The front surface 221 can have any number orvariety of openings to deliver a flow of gases toward the susceptorassembly 240. The gas distribution assembly 220 also includes an outerperipheral edge 224 which in the embodiments shown, is substantiallyround.

The specific type of gas distribution assembly 220 used can varydepending on the particular process being used. Embodiments of thedisclosure can be used with any type of processing system where the gapbetween the susceptor and the gas distribution assembly is controlled.While various types of gas distribution assemblies can be employed(e.g., showerheads), embodiments of the disclosure may be particularlyuseful with spatial gas distribution assemblies which have a pluralityof substantially parallel gas channels. As used in this specificationand the appended claims, the term “substantially parallel” means thatthe elongate axis of the gas channels extend in the same generaldirection. There can be slight imperfections in the parallelism of thegas channels. In a binary reaction, the plurality of substantiallyparallel gas channels can include at least one first reactive gas Achannel, at least one second reactive gas B channel, at least one purgegas P channel and/or at least one vacuum V channel. The gases flowingfrom the first reactive gas A channel(s), the second reactive gas Bchannel(s) and the purge gas P channel(s) are directed toward the topsurface of the wafer. Some of the gas flow moves horizontally across thesurface of the wafer and out of the process region through the purge gasP channel(s). A substrate moving from one end of the gas distributionassembly to the other end will be exposed to each of the process gasesin turn, forming a layer on the substrate surface.

In some embodiments, the gas distribution assembly 220 is a rigidstationary body made of a single injector unit. In one or moreembodiments, the gas distribution assembly 220 is made up of a pluralityof individual sectors (e.g., injector units 222), as shown in FIG. 3.Either a single piece body or a multi-sector body can be used with thevarious embodiments of the disclosure described.

A susceptor assembly 240 is positioned beneath the gas distributionassembly 220. The susceptor assembly 240 includes a top surface 241 andat least one recess 242 in the top surface 241. The susceptor assembly240 also has a bottom surface 243 and an edge 244. The at least onerecess 242 can be any suitable shape and size depending on the shape andsize of the substrates 60 being processed. In the embodiment shown inFIG. 2, the recess 242 has a flat bottom to support the bottom of thewafer; however, the bottom of the recess can vary. In some embodiments,the recess has step regions around the outer peripheral edge of therecess which are sized to support the outer peripheral edge of thewafer. The amount of the outer peripheral edge of the wafer that issupported by the steps can vary depending on, for example, the thicknessof the wafer and the presence of features already present on the backside of the wafer.

In some embodiments, as shown in FIG. 2, the recess 242 in the topsurface 241 of the susceptor assembly 240 is sized so that a substrate60 supported in the recess 242 has a top surface 61 substantiallycoplanar with the top surface 241 of the susceptor 240. As used in thisspecification and the appended claims, the term “substantially coplanar”means that the top surface of the wafer and the top surface of thesusceptor assembly are coplanar within ±0.2 mm. In some embodiments, thetop surfaces are coplanar within 0.5 mm, ±0.4 mm, ±0.35 mm, ±0.30 mm,±0.25 mm, ±0.20 mm, ±0.15 mm, ±0.10 mm or ±0.05 mm.

The susceptor assembly 240 of FIG. 2 includes a support post 260 whichis capable of lifting, lowering and rotating the susceptor assembly 240.The susceptor assembly may include a heater, or gas lines, or electricalcomponents within the center of the support post 260. The support post260 may be the primary means of increasing or decreasing the gap betweenthe susceptor assembly 240 and the gas distribution assembly 220, movingthe susceptor assembly 240 into proper position. The susceptor assembly240 may also include fine tuning actuators 262 which can makemicro-adjustments to susceptor assembly 240 to create a predeterminedgap 270 between the susceptor assembly 240 and the gas distributionassembly 220.

In some embodiments, the gap 270 distance is in the range of about 0.1mm to about 5.0 mm, or in the range of about 0.1 mm to about 3.0 mm, orin the range of about 0.1 mm to about 2.0 mm, or in the range of about0.2 mm to about 1.8 mm, or in the range of about 0.3 mm to about 1.7 mm,or in the range of about 0.4 mm to about 1.6 mm, or in the range ofabout 0.5 mm to about 1.5 mm, or in the range of about 0.6 mm to about1.4 mm, or in the range of about 0.7 mm to about 1.3 mm, or in the rangeof about 0.8 mm to about 1.2 mm, or in the range of about 0.9 mm toabout 1.1 mm, or about 1 mm.

The processing chamber 200 shown in the Figures is a carousel-typechamber in which the susceptor assembly 240 can hold a plurality ofsubstrates 60. As shown in FIG. 3, the gas distribution assembly 220 mayinclude a plurality of separate injector units 222, each injector unit222 being capable of depositing a film on the wafer, as the wafer ismoved beneath the injector unit. Two pie-shaped injector units 222 areshown positioned on approximately opposite sides of and above thesusceptor assembly 240. This number of injector units 222 is shown forillustrative purposes only. It will be understood that more or lessinjector units 222 can be included. In some embodiments, there are asufficient number of pie-shaped injector units 222 to form a shapeconforming to the shape of the susceptor assembly 240. In someembodiments, each of the individual pie-shaped injector units 222 may beindependently moved, removed and/or replaced without affecting any ofthe other injector units 222. For example, one segment may be raised topermit a robot to access the region between the susceptor assembly 240and gas distribution assembly 220 to load/unload substrates 60.

Processing chambers having multiple gas injectors can be used to processmultiple wafers simultaneously so that the wafers experience the sameprocess flow. For example, as shown in FIG. 4, the processing chamber200 has four gas injector assemblies and four substrates 60. At theoutset of processing, the substrates 60 can be positioned between thegas distribution assemblies 220. Rotating 17 the susceptor assembly 240by 45° will result in each substrate 60 which is between gasdistribution assemblies 220 to be moved to a gas distribution assembly220 for film deposition, as illustrated by the dotted circle under thegas distribution assemblies 220. An additional 45° rotation would movethe substrates 60 away from the gas distribution assemblies 220. Thenumber of substrates 60 and gas distribution assemblies 220 can be thesame or different. In some embodiments, there are the same numbers ofwafers being processed as there are gas distribution assemblies. In oneor more embodiments, the number of wafers being processed are fractionof or an integer multiple of the number of gas distribution assemblies.For example, if there are four gas distribution assemblies, there are 4×wafers being processed, where x is an integer value greater than orequal to one. In an exemplary embodiment, the gas distribution assembly220 includes eight process regions separated by gas curtains and thesusceptor assembly 240 can hold six wafers.

The processing chamber 200 shown in FIG. 4 is merely representative ofone possible configuration and should not be taken as limiting the scopeof the disclosure. Here, the processing chamber 200 includes a pluralityof gas distribution assemblies 220. In the embodiment shown, there arefour gas distribution assemblies 220 (also called injector assemblies)evenly spaced about the processing chamber 200. The processing chamber200 shown is octagonal; however, those skilled in the art willunderstand that this is one possible shape and should not be taken aslimiting the scope of the disclosure. The gas distribution assemblies220 shown are trapezoidal, but can be a single circular component ormade up of a plurality of pie-shaped segments, like that shown in FIG.3.

The embodiment shown in FIG. 4 includes a load lock chamber 280, or anauxiliary chamber like a buffer station. This chamber 280 is connectedto a side of the processing chamber 200 to allow, for example thesubstrates (also referred to as substrates 60) to be loaded/unloadedfrom the processing chamber 200. A wafer robot may be positioned in thechamber 280 to move the substrate onto the susceptor.

Rotation of the carousel (e.g., the susceptor assembly 240) can becontinuous or intermittent (discontinuous). In continuous processing,the wafers are constantly rotating so that they are exposed to each ofthe injectors in turn. In discontinuous processing, the wafers can bemoved to the injector region and stopped, and then to the region 84between the injectors and stopped. For example, the carousel can rotateso that the wafers move from an inter-injector region across theinjector (or stop adjacent the injector) and on to the nextinter-injector region where the carousel can pause again. Pausingbetween the injectors may provide time for additional processingroutines between each layer deposition (e.g., exposure to plasma).

FIG. 5 shows a sector or portion of a gas distribution assembly 220,which may be referred to as an injector unit. The injector units 222 canbe used individually or in combination with other injector units. Forexample, as shown in FIG. 6, four of the injector units 222 of FIG. 5are combined to form a single gas distribution assembly 220. (The linesseparating the four injector units are not shown for clarity.) While theinjector unit 222 of FIG. 5 has both a first reactive gas port 225 and asecond gas port 235 in addition to purge gas ports 255 and vacuum ports245, an injector unit 222 does not need all of these components.

Referring to both FIGS. 5 and 6, a gas distribution assembly 220 inaccordance with one or more embodiment may comprise a plurality ofsectors (or injector units 222) with each sector being identical ordifferent. The gas distribution assembly 220 is positioned within theprocessing chamber and comprises a plurality of elongate gas ports 225,235, 245 in a front surface 221 of the gas distribution assembly 220.The plurality of elongate gas ports 225, 235, 245, 255 extend from anarea adjacent the inner peripheral edge 223 toward an area adjacent theouter peripheral edge 224 of the gas distribution assembly 220. Theplurality of gas ports shown include a first reactive gas port 225, asecond gas port 235, a vacuum port 245 which surrounds each of the firstreactive gas ports and the second reactive gas ports and a purge gasport 255.

With reference to the embodiments shown in FIG. 5 or 6, when statingthat the ports extend from at least about an inner peripheral region toat least about an outer peripheral region, however, the ports can extendmore than just radially from inner to outer regions. The ports canextend tangentially as vacuum port 245 surrounds reactive gas port 225and reactive gas port 235. In the embodiment shown in FIGS. 5 and 6, thewedge shaped reactive gas ports 225, 235 are surrounded on all edges,including adjacent the inner peripheral region and outer peripheralregion, by a vacuum port 245.

Referring to FIG. 5, as a substrate moves along path 227, each portionof the substrate surface is exposed to the various reactive gases. Tofollow the path 227, the substrate will be exposed to, or “see”, a purgegas port 255, a vacuum port 245, a first reactive gas port 225, a vacuumport 245, a purge gas port 255, a vacuum port 245, a second gas port 235and a vacuum port 245. Thus, at the end of the path 227 shown in FIG. 5,the substrate has been exposed to the first reactive gas and the secondreactive gas to form a layer. The injector unit 222 shown makes aquarter circle but could be larger or smaller. The gas distributionassembly 220 shown in FIG. 6 can be considered a combination of four ofthe injector units 222 of FIG. 3 connected in series.

The injector unit 222 of FIG. 5 shows a gas curtain 250 that separatesthe reactive gases. The term “gas curtain” is used to describe anycombination of gas flows or vacuum that separate reactive gases frommixing. The gas curtain 250 shown in FIG. 5 comprises the portion of thevacuum port 245 next to the first reactive gas port 225, the purge gasport 255 in the middle and a portion of the vacuum port 245 next to thesecond gas port 235. This combination of gas flow and vacuum can be usedto prevent or minimize gas phase reactions of the first reactive gas andthe second reactive gas.

Referring to FIG. 6, the combination of gas flows and vacuum from thegas distribution assembly 220 form a separation into a plurality ofprocess regions 350. The process regions are roughly defined around theindividual gas ports 225, 235 with the gas curtain 250 between 350. Theembodiment shown in FIG. 6 makes up eight separate process regions 350with eight separate gas curtains 250 between. A processing chamber canhave at least two process regions. In some embodiments, there are atleast three, four, five, six, seven, eight, nine, 10, 11 or 12 processregions.

During processing a substrate may be exposed to more than one processregion 350 at any given time. However, the portions that are exposed tothe different process regions will have a gas curtain separating thetwo. For example, if the leading edge of a substrate enters a processregion including the second gas port 235, a middle portion of thesubstrate will be under a gas curtain 250 and the trailing edge of thesubstrate will be in a process region including the first reactive gasport 225.

A factory interface (as shown in FIG. 4), which can be, for example, aload lock chamber 280, is shown connected to the processing chamber 200.A substrate 60 is shown superimposed over the gas distribution assembly220 to provide a frame of reference. The substrate 60 may often sit on asusceptor assembly to be held near the front surface 221 of the gasdistribution assembly 220. The substrate 60 is loaded via the factoryinterface into the processing chamber 200 onto a substrate support orsusceptor assembly (see FIG. 4). The substrate 60 can be shownpositioned within a process region because the substrate is locatedadjacent the first reactive gas port 225 and between two gas curtains250 a, 250 b. Rotating the substrate 60 along path 227 will move thesubstrate counter-clockwise around the processing chamber 200. Thus, thesubstrate 60 will be exposed to the first process region 350 a throughthe eighth process region 350 h, including all process regions between.

Some embodiments of the disclosure are directed to a processing chamber200 with a plurality of process regions 350 a-350 h with each processregion separated from an adjacent region by a gas curtain 250. Forexample, the processing chamber shown in FIG. 6. The number of gascurtains and process regions within the processing chamber can be anysuitable number depending on the arrangement of gas flows. Theembodiment shown in FIG. 6 has eight gas curtains 250 and eight processregions 350 a-350 h.

Referring back to FIG. 1, the processing platform 100 includes atreatment chamber 140 connected to a second side 112 of the centraltransfer station 110. The treatment chamber 140 of some embodiments isconfigured to expose the wafers to a process to treat the wafers beforeand/or after processing in first batch processing chamber 120. Thetreatment chamber 140 of some embodiments comprises an annealingchamber. The annealing chamber can be a furnace annealing chamber or arapid thermal annealing chamber, or a different chamber configured tohold a wafer at a predetermined temperature and pressure and provide aflow of gas to the chamber.

In some embodiments, the processing platform further comprises a secondbatch processing chamber 130 connected to a third side 113 of thecentral transfer station 110. The second batch processing chamber 130can be configured similarly to the first batch processing chamber 120,or can be configured to perform a different process or to processdifferent numbers of substrates.

The second batch processing chamber 130 can be the same as the firstbatch processing chamber 120 or different. In some embodiments, thefirst batch processing chamber 120 and the second batch processingchamber 130 are configured to perform the same process with the samenumber of wafers in the same batch time so that x (the number of wafersin the first batch processing chamber 120) and y (the number of wafersin the second batch processing chamber 130) are the same and the firstbatch time and second batch time (of the second batch processing chamber130) are the same. In some embodiments, the first batch processingchamber 120 and the second batch processing chamber 130 are configuredto have one or more of different numbers of wafers (x not equal to y),different batch times, or both.

In the embodiment shown in FIG. 1, the processing platform 100 includesa second treatment chamber 150 connected to a fourth side 114 of thecentral transfer station 110. The second treatment chamber 150 can bethe same as the treatment chamber 140 or different.

The processing platform 100 can include a controller 195 connected tothe robot 117 (the connection is not shown). The controller 195 can beconfigured to move wafers between the treatment chamber 140 and thefirst batch processing chamber 120 with a first arm 118 of the robot117. In some embodiments, the controller 195 is also configured to movewafers between the second treatment chamber 150 and the second batchprocessing chamber 130 with a second arm 119 of the robot 117.

In some embodiments, the controller 195 is connected to the susceptorassembly 240 and the gas distribution assembly 220 of a processingchamber 200. The controller 195 can be configured to rotate 17 thesusceptor assembly 240 about a central axis. The controller can also beconfigured to control the gas flows in the gas ports 225, 235, 245, 255.In some embodiments, the first reactive gas port 225 provides a flow ofa metal precursor. In some embodiments, the second reactive gas port 235provides a flow of a reactant. In some embodiments, other gas ports (notlabelled) may provide a flow of a plasma. The first reactive gas port225, the second reactive gas port 235 and the other reactive gas ports(not labelled) may be arranged in any processing order.

The processing platform 100 can also include a first buffer station 151connected to a fifth side 115 of the central transfer station 110 and/ora second buffer station 152 connected to a sixth side 116 of the centraltransfer station 110. The first buffer station 151 and second bufferstation 152 can perform the same or different functions. For example,the buffer stations may hold a cassette of wafers which are processedand returned to the original cassette, or the first buffer station 151may hold unprocessed wafers which are moved to the second buffer station152 after processing. In some embodiments, one or more of the bufferstations are configured to pre-treat, pre-heat or clean the wafersbefore and/or after processing.

In some embodiments, the controller 195 is configured to move wafersbetween the first buffer station 151 and one or more of the treatmentchamber 140 and the first batch processing chamber 120 using the firstarm 118 of the robot 117. In some embodiments, the controller 195 isconfigured to move wafers between the second buffer station 152 and oneor more of the second treatment chamber 150 or the second batchprocessing chamber 130 using the second arm 119 of the robot 117.

The processing platform 100 may also include one or more slit valves 160between the central transfer station 110 and any of the processingchambers. In the embodiment shown, there is a slit valve 160 betweeneach of the processing chambers 120, 130, 140, 150 and the centraltransfer station 110. The slit valves 160 can open and close to isolatethe environment within the processing chamber from the environmentwithin the central transfer station 110. For example, if the processingchamber will generate plasma during processing, it may be helpful toclose the slit valve for that processing chamber to prevent stray plasmafrom damaging the robot in the transfer station.

In some embodiments, the processing chambers are not readily removablefrom the central transfer station 110. To allow maintenance to beperformed on any of the processing chambers, each of the processingchambers may further include a plurality of access doors 170 on sides ofthe processing chambers. The access doors 170 allow manual access to theprocessing chamber without removing the processing chamber from thecentral transfer station 110. In the embodiment shown, each side of eachof the processing chamber, except the side connected to the transferstation, have an access door 170. The inclusion of so many access doors170 can complicate the construction of the processing chambers employedbecause the hardware within the chambers would need to be configured tobe accessible through the doors.

The processing platform of some embodiments includes a water box 180connected to the central transfer station 110. The water box 180 can beconfigured to provide a coolant to any or all of the processingchambers. Although referred to as a “water” box, those skilled in theart will understand that any coolant can be used.

In some embodiments, the size of the processing platform 100 allows forthe connection to house power through a single power connector 190. Thesingle power connector 190 attaches to the processing platform 100 toprovide power to each of the processing chambers and the centraltransfer station 110.

The processing platform 100 can be connected to a factory interface 102to allow wafers or cassettes of wafers to be loaded into the processingplatform 100. A robot 103 within the factory interface 102 can be movedthe wafers or cassettes into and out of the buffer stations 151, 152.The wafers or cassettes can be moved within the processing platform 100by the robot 117 in the central transfer station 110. In someembodiments, the factory interface 102 is a transfer station of anothercluster tool.

In some embodiments, the processing platform 100 or first batchprocessing chamber 120 is connected to a controller. The controller canbe the same controller 195 or a different controller. The controller canbe coupled to the susceptor assembly and the gas distribution assemblyof the first batch processing chamber 120 and has one or moreconfigurations. The configurations can include, but are not limited to,a first configuration to rotate the susceptor assembly about the centralaxis, a second configuration to provide a flow of a metal precursor to aprocess region, a third configuration to provide a flow of a reactant toa process region, a fourth configuration to provide a plasma in aprocess region.

FIG. 7 depicts a generalized method for forming a metal film on asubstrate in accordance with one or more embodiment of the disclosure.The method 700 generally begins at 702, where a substrate upon which ametal film is to be formed is provided and placed into a processingchamber. As used herein, a “substrate surface” refers to any substratesurface upon which a layer may be formed. The substrate surface may haveone or more features formed therein, one or more layers formed thereon,and combinations thereof. The substrate (or substrate surface) may bepretreated prior to the deposition of the metal film, for example, bypolishing, etching, reduction, oxidation, halogenation, hydroxylation,annealing, baking, or the like.

The substrate may be any substrate capable of having material depositedthereon, such as a silicon substrate, a III-V compound substrate, asilicon germanium (SiGe) substrate, an epi-substrate, asilicon-on-insulator (SOI) substrate, a display substrate such as aliquid crystal display (LCD), a plasma display, an electro luminescence(EL) lamp display, a solar array, solar panel, a light emitting diode(LED) substrate, a semiconductor wafer, or the like. In someembodiments, one or more additional layers may be disposed on thesubstrate such that the metal film may be, at least partially, formedthereon. For example, in some embodiments, a layer comprising a metal, anitride, an oxide, or the like, or combinations thereof may be disposedon the substrate and may have the metal film formed upon such layer orlayers.

At 703, the substrate is optionally exposed to a blocking compound. Thisprocess step is described more fully below and may be useful forcontrolling the selectivity of the deposition process on a substratecomprising both a metal surface and a dielectric surface.

At 704, a metal film is formed on the substrate. The metal film may beformed via a cyclical deposition process, such as atomic layerdeposition (ALD), or the like. In some embodiments, the forming of ametal film via a cyclical deposition process may generally compriseexposing the substrate to two or more process gases separately. Intime-domain ALD embodiments, exposure to each of the process gases areseparated by a time delay/pause to allow the components of the processgases to adhere and/or react on the substrate surface. Alternatively, orin combination, in some embodiments, a purge may be performed beforeand/or after the exposure of the substrate to the process gases, whereinan inert gas is used to perform the purge. For example, a first processgas may be provided to the process chamber followed by a purge with aninert gas. Next, a second process gas may be provided to the processchamber followed by a purge with an inert gas. In some embodiments, theinert gas may be continuously provided to the process chamber and thefirst process gas may be dosed or pulsed into the process chamberfollowed by a dose or pulse of the second process gas into the processchamber. In such embodiments, a delay or pause may occur between thedose of the first process gas and the second process gas, allowing thecontinuous flow of inert gas to purge the process chamber between dosesof the process gases.

In spatial ALD embodiments, exposure to each of the process gases occurssimultaneously to different parts of the substrate so that one part ofthe substrate is exposed to the first reactive gas while a differentpart of the substrate is exposed to the second reactive gas (if only tworeactive gases are used). The substrate is moved relative to the gasdelivery system so that each point on the substrate is sequentiallyexposed to both the first and second reactive gases. In any embodimentof a time-domain ALD or spatial ALD process, the sequence may berepeated until a predetermined layer thickness is formed on thesubstrate surface.

A “pulse” or “dose” as used herein is intended to refer to a quantity ofa source gas that is intermittently or non-continuously introduced intothe process chamber. The quantity of a particular compound within eachpulse may vary over time, depending on the duration of the pulse. Aparticular process gas may include a single compound or amixture/combination of two or more compounds, for example, the processgases described below.

The durations for each pulse/dose are variable and may be adjusted toaccommodate, for example, the volume capacity of the processing chamberas well as the capabilities of a vacuum system coupled thereto.Additionally, the dose time of a process gas may vary according to theflow rate of the process gas, the temperature of the process gas, thetype of control valve, the type of process chamber employed, as well asthe ability of the components of the process gas to adsorb onto thesubstrate surface. Dose times may also vary based upon the type of layerbeing formed and the geometry of the device being formed. A dose timeshould be long enough to provide a volume of compound sufficient toadsorb/chemisorb onto substantially the entire surface of the substrateand form a layer of a process gas component thereon.

The process of forming the metal film at 704 may begin by exposing thesubstrate to a first reactive gas. The first reactive gas comprises analkyl halide and is exposed to the substrate for a first period of time,as shown at 706.

The alkyl halide may be any suitable reactant to adsorb a layer ofhalogen on the substrate for later reaction. In some embodiments, thealkyl halide comprises carbon and halogen. In some embodiments, thehalogen comprises bromine or iodine. In some embodiments, the halogen isinsoluble in the metal film. As used in this regard, a halogen which isinsoluble in a metal film comprises less than or equal to about 2%, lessthan or equal to about 1%, or less than or equal to about 0.5% of themetal film on an atomic basis. In some embodiments, the alkyl halide hasthe general formula R—X, where R is an alkyl, alkenyl, aryl, or othercarbonaceous group. In some embodiments,

R comprises one to two, one to four, or one to six carbon atoms. In someembodiments, the alkyl halide comprises or consists essentially ofiodoethane (H₅C₂I) or diiodomethane (CH₂I₂). As used in this regard, analkyl halide which consists essentially of a stated species comprisesgreater than 95%, 98%, 99% or 99.5% of the stated species on a molarbasis, excluding any inert diluent gases.

The alkyl halide is delivered to the processing chamber as an alkylhalide containing gas. The alkyl halide containing gas may be providedin one or more pulses or continuously. The flow rate of the alkyl halidecontaining gas can be any suitable flow rate including, but not limitedto, flow rates is in the range of about 1 to about 5000 sccm, or in therange of about 2 to about 4000 sccm, or in the range of about 3 to about3000 sccm or in the range of about 5 to about 2000 sccm. The alkylhalide containing gas can be provided at any suitable pressureincluding, but not limited to, a pressure in the range of about 5 mTorrto about 25 Torr, or in the range of about 100 mTorr to about 20 Torr,or in the range of about 5 Torr to about 20 Torr, or in the range ofabout 50 mTorr to about 2000 mTorr, or in the range of about 100 mTorrto about 1000 mTorr, or in the range of about 200 mTorr to about 500mTorr.

The period of time that the substrate is exposed to the alkyl halidecontaining gas may be any suitable amount of time necessary to allow thealkyl halide to form an adequate adsorption layer atop the substratesurface(s). For example, the process gas may be flowed into the processchamber for a period of about 0.1 seconds to about 90 seconds. In sometime-domain ALD processes, the alkyl halide containing gas is exposedthe substrate surface for a time in the range of about 0.1 sec to about90 sec, or in the range of about 0.5 sec to about 60 sec, or in therange of about 1 sec to about 30 sec, or in the range of about 2 sec toabout 25 sec, or in the range of about 3 sec to about 20 sec, or in therange of about 4 sec to about 15 sec, or in the range of about 5 sec toabout 10 sec.

In some embodiments, an inert gas may additionally be provided to theprocess chamber at the same time as the alkyl halide containing gas. Theinert gas may be mixed with the alkyl halide containing gas (e.g., as adiluent gas) or be provided separately and can be pulsed or of aconstant flow. In some embodiments, the inert gas is flowed into theprocessing chamber at a constant flow in the range of about 1 to about10000 sccm. The inert gas may be any inert gas, for example, such asargon, helium, neon, or combinations thereof.

The temperature of the substrate during deposition can be controlled,for example, by setting the temperature of the substrate support orsusceptor. In some embodiments the substrate is held at a temperature inthe range of about 0° C. to about 600° C., or in the range of about 25°C. to about 500° C., or in the range of about 50° C. to about 450° C.,or in the range of about 100° C. to about 400° C., or in the range ofabout 200° C. to about 400° C., or in the range of about 250° C. toabout 350° C. In some embodiments, the substrate is maintained at atemperature below the decomposition temperature of the metal precursor.In some embodiments, the substrate is maintained at a temperature belowthe decomposition temperature of the alkyl halide. In some embodiments,the substrate is maintained at a temperature between the decompositiontemperature of the alkyl halide and the decomposition temperature of themetal precursor.

In one or more embodiments, the substrate is maintained at a temperatureless than or equal to about 400° C., or less than or equal to about 350°C., or less than about 300° C. In one or more embodiments, the substrateis maintained at a temperature greater than or equal to about 250° C.,or greater than or equal to about 300° C., or greater than about 350° C.In some embodiments, the substrate is maintained at a temperature ofabout 280° C.

In addition to the foregoing, additional process parameters may beregulated while exposing the substrate to the alkyl halide containinggas. For example, in some embodiments, the process chamber may bemaintained at a pressure of about 0.2 to about 100 Torr, or in the rangeof about 0.3 to about 90 Torr, or in the range of about 0.5 to about 80Torr, or in the range of about 1 to about 50 Torr.

Next, at 708, the process chamber (especially in time-domain ALD) may bepurged using an inert gas. (This may not be needed in spatial ALDprocesses as there are gas curtains separating the reactive gases.) Theinert gas may be any inert gas, for example, such as argon, helium,neon, or the like. In some embodiments, the inert gas may be the same,or alternatively, may be different from the inert gas provided to theprocess chamber during the exposure of the substrate to the alkyl halidecontaining gas at 706. In embodiments where the inert gas is the same,the purge may be performed by diverting the first process gas from theprocess chamber, allowing the inert gas to flow through the processchamber, purging the process chamber of any excess first process gascomponents or reaction byproducts. In some embodiments, the inert gasmay be provided at the same flow rate used in conjunction with the firstprocess gas, described above, or in some embodiments, the flow rate maybe increased or decreased. For example, in some embodiments, the inertgas may be provided to the process chamber at a flow rate of about 0 toabout 10000 sccm to purge the process chamber. In spatial ALD, purge gascurtains are maintained between the flows of reactive gases and purgingthe process chamber may not be necessary. In some embodiments of aspatial ALD process, the process chamber or region of the processchamber may be purged with an inert gas.

The flow of inert gas may facilitate removing any excess first processgas components and/or excess reaction byproducts from the processchamber to prevent unwanted gas phase reactions of the first and secondprocess gases.

Next, at 710, the substrate is exposed to a second process gas for asecond period of time. The second process gas comprises a metalprecursor which reacts with the adsorbed layer of halogen on thesubstrate surface to deposit a metal film. The second reactive gas mayalso be referred to as the metal precursor gas.

The metal precursor may be any suitable precursor to react with theadsorbed halogen layer on the substrate. In some embodiments, the metalprecursor comprises a metal center and one or more ligands. In someembodiments, the metal center comprises one or more metal atoms. Stateddifferently, in some embodiments, the metal precursor is one or more ofa dimer, trimer or tetramer.

The metal precursor can be any suitable precursor with a decompositiontemperature above the deposition temperature. In some embodiments, themetal precursor comprises substantially no oxygen or nitrogen atoms.Accordingly, in these embodiments, the metal precursor comprises nocarbonyl, oxo, amine, or imine ligands. Within these parameters, thenumber of ligands and types of ligands on the metal precursor can vary,based on, for example, the oxidation state of the metal atom. The metalprecursor can be homoleptic or heteroleptic. In some embodiments, themetal precursor comprises at least one ligand comprising an optionallyalkyl substituted cyclopentadiene (Cp) ring. In some embodiments, themetal precursor comprises at least one ligand comprising an optionallyalkyl substituted benzene ring. In some embodiments, the metal precursorcomprises at least one p-cymene ligand. In some embodiments, the metalprecursor comprises at least one ligand comprising an open or closeddiene. In some embodiments, the metal precursor comprises at least one1,3-butadiene ligand. In some embodiments, the metal precursor comprisesat least one 1,5-hexadiene ligand. In some embodiments, the metalprecursor comprises at least one aromatic ligand. In some embodiments,the at least one aromatic ligand comprises a benzene ring. In someembodiments, the benzene ring comprises at least one organic substituentcomprising in the range of 1 to 6 carbon atoms. In some embodiments, thearomatic ligand comprises at least one ethylbenzene ligand. In someembodiments, the metal precursor comprises or consists essentially ofbis(ethylbenzene)molybdenum. In some embodiments, the metal precursorcomprises or consists essentially of p-cymene ruthenium 1,5-hexadiene.

The metal of the metal precursor corresponds to the metal of thedeposited metal film. In some embodiments, the metal is selected frommolybdenum, ruthenium, cobalt, copper, platinum, nickel or tungsten. Insome embodiments, the metal of the metal precursor has an oxidationstate of 0. Stated differently, in some embodiments, the metal precursorcomprises a zero-valent metal complex.

Additional process parameters may be regulated while exposing thesubstrate to the metal precursor gas. For example, in some embodiments,the process chamber may be maintained at a pressure of about 0.2 toabout 100 Torr, or in the range of about 0.3 to about 90 Torr, or in therange of about 0.5 to about 80 Torr, or in the range of about 1 to about50 Torr.

The metal precursor is delivered to the processing chamber as a metalprecursor gas. The metal precursor gas may be provided in one or morepulses or continuously. The flow rate of the metal precursor gas can beany suitable flow rate including, but not limited to, flow rates is inthe range of about 1 to about 5000 sccm, or in the range of about 2 toabout 4000 sccm, or in the range of about 3 to about 3000 sccm or in therange of about 5 to about 2000 sccm. The metal precursor gas can beprovided at any suitable pressure including, but not limited to, apressure in the range of about 5 mTorr to about 25 Torr, or in the rangeof about 100 mTorr to about 20 Torr, or in the range of about 5 Torr toabout 20 Torr, or in the range of about 50 mTorr to about 2000 mTorr, orin the range of about 100 mTorr to about 1000 mTorr, or in the range ofabout 200 mTorr to about 500 mTorr.

The period of time that the substrate is exposed to the metal precursorgas may be any suitable amount of time necessary to allow the metalprecursor to react with the adsorbed halogen on the substrate surface.For example, the process gas may be flowed into the process chamber fora period of about 0.1 seconds to about 90 seconds. In some time-domainALD processes, the metal precursor gas is exposed the substrate surfacefor a time in the range of about 0.1 sec to about 90 sec, or in therange of about 0.5 sec to about 60 sec, or in the range of about 1 secto about 30 sec, or in the range of about 2 sec to about 25 sec, or inthe range of about 3 sec to about 20 sec, or in the range of about 4 secto about 15 sec, or in the range of about 5 sec to about 10 sec.

In some embodiments, an inert gas may additionally be provided to theprocess chamber at the same time as the metal precursor gas. The inertgas may be mixed with the metal precursor gas (e.g., as a diluent gas)or be provided separately and can be pulsed or of a constant flow. Insome embodiments, the inert gas is flowed into the processing chamber ata constant flow in the range of about 1 to about 10000 sccm. The inertgas may be any inert gas, for example, such as argon, helium, neon, orcombinations thereof.

Next, at 712, the process chamber may be purged using an inert gas. Theinert gas may be any inert gas, for example, such as argon, helium,neon, or the like. In some embodiments, the inert gas may be the same,or alternatively, may be different from the inert gas provided to theprocess chamber during previous process routines. In embodiments wherethe inert gas is the same, the purge may be performed by diverting thesecond process gas from the process chamber, allowing the inert gas toflow through the process chamber, purging the process chamber of anyexcess second process gas components or reaction byproducts. In someembodiments, the inert gas may be provided at the same flow rate used inconjunction with the second process gas, described above, or in someembodiments, the flow rate may be increased or decreased. For example,in some embodiments, the inert gas may be provided to the processchamber at a flow rate of greater than 0 to about 10,000 sccm to purgethe process chamber.

While the generic embodiment of the processing method shown in FIG. 7includes only two pulses of reactive gases, it will be understood thatthis is merely exemplary and that additional pulses of reactive gasesmay be used. In some embodiments, the method is performed without theuse of an oxygen-containing reactive gas. The sub processes of 704comprise a cycle. A cycle may be performed in any order as long as thereactive gases are separated by a purge of the processing chamber. Insome embodiments, the metal film is deposited at rate greater than orequal to about 0.2 Å/cycle, greater than or equal to about 0.3 Å/cycle,greater than or equal to about 0.4 Å/cycle, greater than or equal toabout 0.5 Å/cycle, greater than or equal to about 0.6 Å/cycle, greaterthan or equal to about 0.7 Å/cycle, greater than or equal to about 0.8Å/cycle, greater than or equal to about 0.9 Å/cycle, greater than orequal to about 1.0 Å/cycle, or greater than or equal to about 1.2Å/cycle.

The deposition process is performed as a thermal process without the useof plasma reactants. Stated differently, in some embodiments, the methodis performed without plasma.

Next, at 714, it is determined whether the metal film has achieved apredetermined thickness. If the predetermined thickness has not beenachieved, the method 700 returns to 704 to continue forming the metalfilm until the predetermined thickness is reached. Once thepredetermined thickness has been reached, the method 700 can either endor proceed to 716 for optional further processing (e.g., bulk depositionof another metal film). In some embodiments, the metal film may bedeposited to form a total layer thickness of about 10 Å to about 10,000Å, or in some embodiments, about 10 Å to about 1000 Å, or in someembodiments, about 50 Å to about 5,000 Å.

In some embodiments, the metal layer comprises greater than or equal toabout 75 atomic % molybdenum, or greater than or equal to about 80atomic % molybdenum, or greater than or equal to about 85 atomic %molybdenum, or greater than or equal to about 90 atomic % molybdenum, orgreater than or equal to about 95 atomic % molybdenum.

In some embodiments, the metal layer comprises less than or equal toabout 10 atomic % oxygen, or less than or equal to about 9 atomic %oxygen, or less than or equal to about 8 atomic % oxygen, or less thanor equal to about 7 atomic % oxygen, or less than or equal to about 6atomic % oxygen, or less than or equal to about 5 atomic % oxygen, orless than or equal to about 4 atomic % oxygen, or less than or equal toabout 3 atomic % oxygen.

In some embodiments, the metal layer comprises in the range of about0.02 to about 5 atomic % iodine, or less than or equal to about 1 atomic% iodine.

In some embodiments, the metal layer comprises less than or equal toabout 20 atomic % carbon, or less than or equal to about 15 atomic %carbon, or less than or equal to about 10 atomic % carbon, or less thanor equal to about 5 atomic % carbon.

In some embodiments, the metal layer comprises greater than or equal toabout 90 atomic % molybdenum, less than or equal to about 3 atomic %oxygen, less than or equal to about 1 atomic % iodine and less than orequal to about 10 atomic % carbon.

In some embodiments, the metal layer has a resistivity of less than orequal to about 40 μohm-cm, or less than or equal to about 35 μohm-cm, orless than or equal to about 30 μohm-cm, or less than or equal to about25 μohm-cm, or less than or equal to about 20 μohm-cm. In someembodiments, the metal layer comprises molybdenum and has a resistivityof less than or equal to about 40 μohm-cm, or less than or equal toabout 35 μohm-cm, or less than or equal to about 30 μohm-cm, or lessthan or equal to about 25 μohm-cm, or less than or equal to about 20μohm-cm.

In some embodiments, the metal film is further processed by annealingthe metal film. Without being bound by theory, it is believed thatannealing the film at a high temperature under an Ar or H₂ atmospherereduces carbon and halogen impurities in the metal film. In someembodiments, the metal film is annealed under an atmosphere comprisingargon or hydrogen gas (H₂) to reduce the atomic concentration of carbonand/or halogen impurities.

The metal film deposited by some embodiments is smoother than the filmsdeposited by known oxygen-based deposition processes. In someembodiments, the metal film has a surface roughness of less than orequal to about 10%, less than or equal to about 8%, less than or equalto about 5%, or less than or equal to about 2%, of a thickness of themetal film.

The purity of the metal film is high. In some embodiments, the metalfilm has a carbon content less than or equal to about 2%, less than orequal to about 1%, or less than or equal to about 0.5% carbon on anatomic basis. In some embodiments, the metal film has a halogen contentless than or equal to about 1% or less than or equal to about 0.5%halogen on an atomic basis. In some embodiments, the metal film has apurity of greater than or equal to about 95%, greater than or equal toabout 97%, greater than or equal to about 99%, greater than or equal toabout 99.5%, or greater than or equal to about 99.9% metal atoms on anatomic basis.

Some embodiments of the disclosure selectively deposit a first metalfilm on a second metal surface over a first dielectric surface. Thesemethods are similar to method 700 as described above, except that thesubstrate provided comprises a first dielectric surface and a secondmetal surface. The first metal (of the metal film) and the second metal(of the substrate surface) may be the same metal or may be differentmetals. In some embodiments, the first metal is molybdenum, ruthenium,cobalt, copper, platinum, nickel or tungsten while the second metal istungsten, cobalt or copper.

The first dielectric surface may be formed from any suitable dielectricmaterial. In some embodiments, the dielectric material comprisesnitrogen or oxygen atoms. Without being bound by theory, it is believedthat these materials react with the alkyl halide and prevent the halogenfrom adsorbing onto the substrate surface so as to catalyze the reactionwith the metal precursor. Accordingly, little, if any, metal film isformed on the dielectric surface.

In some embodiments, the deposition temperature is below thedecomposition temperature of the alkyl halide. Again, without beingbound by theory, it is believed that if the alkyl halide decomposes, thehalogen will be available for reaction with the metal precursor on allsurfaces (regardless of composition), leading to metal film depositionon all substrate surfaces, including the dielectric surface. In someembodiments, the deposition temperature is at or above the decompositiontemperature of the alkyl halide.

Some embodiments of the disclosure selectively deposit a first metalfilm on a first dielectric surface over a second metal surface. Thesemethods are similar to method 700 as described above, except that thesubstrate provided comprises a first dielectric surface and a secondmetal surface and the substrate is exposed to a blocking compound at703.

At 703, a substrate comprising at least a second metal surface and afirst dielectric surface is exposed to a blocking compound. The blockingcompound may be any suitable compound for blocking deposition on thesecond metal surface. In some embodiments, the blocking compoundcomprises at least one triple bond between two carbon atoms. Stateddifferently, in some embodiments, the blocking compound comprises analkyne. In some embodiments, the blocking compound has the generalformula of R′≡R″. In some embodiments, R′ and R″ are identical. In someembodiments, R′ and/or R″ are an alkyl or other carbonaceous group. Insome embodiments, the blocking compound comprises 4-12 carbon atoms. Insome embodiments, R′ and/or R″ are linear. In some embodiments, R′and/or R″ are branched. In some embodiments, the blocking compoundcomprises 3-hexyne.

The first metal (of the metal film) and the second metal (of thesubstrate surface) may be the same metal or may be different metals. Insome embodiments, the first metal is molybdenum, ruthenium, cobalt,copper, platinum, nickel or tungsten while the second metal is tungsten,cobalt or copper.

The first dielectric surface may be formed from any suitable dielectricmaterial. In some embodiments, the dielectric material comprisesnitrogen or oxygen atoms.

As mentioned previously, in some embodiments, the deposition temperatureis at or above the decomposition temperature of the alkyl halide. Insome embodiments, the deposition temperature is greater than or equal toabout 250° C., greater than or equal to about 260° C., greater than orequal to about 270° C., greater than or equal to about 280° C., greaterthan or equal to about 290° C., or greater than or equal to about 300°C. In some embodiments, the deposition temperature is in the range ofabout 250° C. to about 450° C., or in the range of about 300° C. toabout 400° C. In some embodiments, the deposition temperature is about350° C.

As stated previously, without being bound by theory, it is believed thatthese materials react with the alkyl halide and prevent the halogen fromadsorbing onto the substrate surface so as to catalyze the reaction withthe metal precursor. Accordingly, little, if any, metal film is formedon the dielectric surface.

However, when the deposition temperature is above the decompositiontemperature of the alkyl halide, the halogen atoms are deposited on theentire substrate surface, thereby allowing deposition on the dielectricsurface. In some embodiments, the metal surface is blocked by theblocking compound, so as to allow little, if any, metal film to beformed on the metal surface. Accordingly, deposition of the metal filmis selective to the dielectric surface over the metal surface,

In general terms, the deposition of highly pure metal films can beunderstood as follows. A substrate, maintained at a depositiontemperature, is exposed to an alkyl halide (R—X) to adsorb R and X onthe substrate, where R is a carbonaceous group and X is a halogen. R isdesorbed in the form of R—R or R⁻, leaving X adsorbed on the substrate.The substrate is exposed to a metal precursor, M—L, where M is the metaland L is a ligand. M—L reacts with the adsorbed X to form M—X on thesubstrate surface, liberating L. M—X reacts with other M—X moieties onthe substrate to form M—M. This reaction may produce either X—X or X.X—X may be desorbed and purged. X⁻ may remain on the surface to furtherreact with M—L.

According to the inventors, this general mechanism relies on severalpremises. First, X is not soluble in M. Without being bound by theory,the insolubility of X confers that X will not be found in appreciablequantity within the final metal film. While it is possible to ignorethis premise (e.g., utilize a halogen soluble in M), using a halogen (X)which is soluble in M is believed to provide metal films with lowerpurity. Second, in terms of bond strength, M—L is weaker than M—X whichis weaker than M—M. Again, without being bound by theory, thesethermodynamic relationships ensure that the reactions identified aboveare thermodynamically favorable. Finally, M—L is thermally stable at thedeposition temperature. Stated differently, the thermal decompositiontemperature of the metal precursor is higher than the depositiontemperature. The theory here states that if the metal precursordecomposes, the deposited film will contain an appreciable quantity ofthe precursor ligand L, typically seen as carbon impurities.

The inventors have surprisingly found that processes including metalprecursors, alkyl halides and process conditions which meet all of theabove requirements deposit highly pure metal films.

Additionally, the inventors have surprisingly found that if thedeposition temperature is below the thermal decomposition temperature ofthe alkyl halide, the deposition process is selective to metal surfacesover dielectric surfaces without requiring the use of a blocking layer.

Further, the inventors have surprisingly found that if the depositiontemperature is at or above the thermal decomposition temperature of thealkyl halide, the deposition process can be made selective by exposingthe metal surface to a small alkyne blocking compound.

Some embodiments of the disclosure advantageously provide methods ofdepositing conformal metal films on substrates comprising high aspectratio structures. As used in this regard, the term “conformal” meansthat the thickness of the metal film is uniform across the substratesurface. As used in this specification and the appended claims, the term“substantially conformal” means that the thickness of the metal filmdoes not vary by more than about 10%, 5%, 2%, 1%, or 0.5% relative tothe average thickness of the film. Stated differently a film which issubstantially conformal has a conformality of greater than about 90%,95%, 98%, 99% or 99.5%.

One or more embodiments of the disclosure are directed to memory devicescomprising a molybdenum conductive layer. In some embodiments, themolybdenum conductive layer comprises greater than or equal to about 90at. % molybdenum, less than or equal to about 3 at. % oxygen, less thanor equal to about 1 at. % iodine and less than or equal to about 10 at.% carbon, and a resistivity less than or equal to about 40 μohm-cm.

In some embodiments, the molybdenum conductive layer is formed on abarrier layer. The barrier layer of some embodiments has a thicknessless than or equal to about 10 Å, 20 Å, 30 Å, 40 Å or 50 Å. In someembodiments, the molybdenum conductive layer is formed on a substratewithout an intervening barrier layer.

The above disclosure relates to the deposition of metal films by asequential pulse of reactants. The following disclosure relates to thedeposition of metal films by a simultaneous or constant-flow process. Insome embodiments, the sequential pulse methods are ALD methods. In someembodiments, the simultaneous or constant-flow methods are CVD methods.While the process steps differ, many of the reactants and processparameters are similar.

FIG. 8 depicts a generalized method 800 for forming a metal film on asubstrate in accordance with one or more embodiment of the disclosure.FIG. 9 depicts an exemplary substrate for processing in accordance withone or more embodiment of the disclosure. The method 800 generallybegins at 810, where a substrate 900 upon which a metal film is to beformed is provided and placed into a processing chamber.

Referring to FIG. 9, an exemplary substrate 900 is shown. In someembodiments, the substrate 900 has a substrate surface 905 with at leastone feature 910 therein. The feature 910 has a sidewall 912, 914 and abottom 916. In some embodiments, a dielectric material 920 forms thesidewall 912, 914 and a metallic material 930 forms the bottom 16.

In some embodiments, the substrate 900 may undergo pre-processing steps.At 815, the substrate may optionally have one or more layers formed onthe substrate surface.

In some embodiments, a metal nitride liner is deposited in the feature910. In some embodiments, the metal nitride liner comprises titaniumnitride. In some embodiments, the metal nitride liner has a thickness ina range of about 15 Å to about 40 Å. In some embodiments, the metalnitride liner has a thickness of about 20 Å or about 30 Å.

In some embodiments, a seed layer is deposited on the substrate surface.In some embodiments, the seed layer is a conformal layer. In someembodiments, the seed layer is continuous. In some embodiments, thethickness of the seed layer is in a range of about 1 nm to about 5 nm,or in a range of about 1 nm to about 4 nm. In some embodiments, the seedlayer comprises a ruthenium layer deposited by a known atomic layerdeposition method. In some embodiments, the seed layer is deposited byan ALD cycle comprising a ruthenium precursor exposure and an alkylhalide exposure with intervening purges. In some embodiments, the seedlayer is deposited by an ALD cycle comprising a ruthenium precursorexposure and an ammonia plasma exposure with intervening purges,

At 820, the substrate is optionally exposed to a blocking compound. Thisprocess step is described more fully below and may be useful forcontrolling the selectivity of the deposition process on a substratecomprising both a metal surface and a dielectric surface.

At 830, a metal film is formed on the substrate. The process of formingthe metal film at 830 may begin by soaking the substrate with acatalytic gas. The catalytic gas comprises an alkyl halide and isexposed to the substrate for a first period of time, as shown at 840.

The alkyl halide may be any suitable reactant to adsorb a layer on thesubstrate for later reaction. Stated differently, soaking the substratein the alkyl halide forms an activated substrate surface. The alkylhalide is described above and elsewhere herein.

The alkyl halide may be provided to the processing chamber in one ormore pulses or continuously. In some embodiments, the alkyl halide isprovided with an inert carrier gas and is referred to the alkyl halidecontaining gas. The flow rate and pressure of the alkyl halide or alkylhalide containing gas can be any suitable values. Exemplary flow ratesand pressures disclosed elsewhere herein for the alkyl halide containinggas are also applicable in this embodiment.

The period of time that the substrate is soaked in the alkyl halide maybe any suitable amount of time necessary to allow the alkyl halide toform an adequate adsorption layer on the substrate surface(s). Forexample, the alkyl halide may be allowed to soak the substrate for aperiod of greater than about 3 seconds or greater than about 5 seconds.In some embodiments, the soak period is in a range of about 3 seconds toabout 60 seconds.

In some embodiments, an inert gas may additionally be provided to theprocess chamber at the same time as the alkyl halide containing gas. Theinert gas may be mixed with the alkyl halide (e.g., as a diluent gas) orbe provided separately and can be pulsed or of a constant flow. Theinert gas may be any inert gas, for example, such as argon, helium,neon, or combinations thereof.

Next, at 850, the substrate is exposed to a second process gas for asecond period of time. The second process gas comprises a metalprecursor which reacts with the adsorbed layer of alkyl halide orhalogen on the substrate surface to deposit a metal film. The secondreactive gas may also be referred to as the metal precursor gas.

The metal precursor may be any suitable precursor to react with theadsorbed alkyl halide layer or halogen layer on the substrate. Suitablemetal precursors are described elsewhere herein.

The metal precursor is delivered to the processing chamber as a metalprecursor gas. The metal precursor gas may be provided in one or morepulses or continuously. The flow rate and pressure of the metalprecursor gas can be any suitable flow rate and pressure. Exemplaryvalues for flow rate and pressure are discussed elsewhere herein.

The period of time that the substrate is exposed to the metal precursorgas may be any suitable amount of time necessary to allow the metalprecursor to react with the adsorbed halogen on the substrate surface.For example, the process gas may be flowed into the process chamber fora period of greater than or equal to about 60 seconds. In someembodiments, the period of exposure to the metal precursor is about 100seconds, about 200 seconds, about 300 seconds, about 400 seconds orabout 500 seconds.

The temperature of the substrate during exposure to the metal precursorcan be controlled, for example, by setting the temperature of thesubstrate support or susceptor. This temperature is also referred to asthe deposition temperature. In some embodiments, the substrate ismaintained at a temperature below the decomposition temperature of themetal precursor. In some embodiments, the substrate is maintained at atemperature below the decomposition temperature of the alkyl halide. Insome embodiments, the substrate is maintained at a temperature betweenthe decomposition temperature of the alkyl halide and the decompositiontemperature of the metal precursor.

In one or more embodiments, the substrate is maintained at a temperatureless than or equal to about 400° C., or less than or equal to about 350°C., or less than or equal to about 300° C., or less than or equal toabout 250° C., or less than or equal to about 200° C. In one or moreembodiments, the substrate is maintained at a temperature greater thanor equal to about 150° C., or greater than or equal to about 200° C., orgreater than or equal to about 250° C., or greater than or equal toabout 300° C., or greater than or equal to about 350° C. In someembodiments, the substrate is maintained at a temperature of about 225°C. or about 280° C.

The deposition process is performed as a thermal process without the useof plasma reactants. Stated differently, the method is performed withoutplasma.

Next, at 860, it is determined whether the metal film has achieved apredetermined thickness. If the predetermined thickness has not beenachieved, the method 800 returns to 850 to continue exposing thesubstrate to the metal precursor until the predetermined thickness isreached. Once the predetermined thickness has been reached, the method800 can either end or proceed to 870 for optional further processing. Insome embodiments, the metal film may be deposited to form a total layerthickness of about 10 Å to about 10,000 Å, or in some embodiments, about20 Å to about 1000 Å, or in some embodiments, about 50 Å to about 200 Å.

Some embodiments of the disclosure selectively deposit a metal film on ametal surface over a first dielectric surface. These methods are similarto method 800 as described above. The substrate provided comprises adielectric surface and a metal surface. In some embodiments, a substrateas shown in FIG. 9 is processed to selectively form bottom up gap fillon the metal surface at the bottom 916 of the feature 910.

The metal of the metal film and the metal of the substrate surface maybe the same metal or may be different metals. The dielectric surface maybe formed from any suitable dielectric material. In some embodiments,the dielectric material comprises nitrogen or oxygen atoms. Withoutbeing bound by theory, it is believed that these materials react withthe alkyl halide and prevent the halogen from adsorbing onto thesubstrate surface so as to catalyze the reaction with the metalprecursor. Accordingly, little, if any, metal film is formed on thedielectric surface.

In some embodiments, the deposition temperature is below thedecomposition temperature of the alkyl halide. Again, without beingbound by theory, it is believed that if the alkyl halide decomposes, thehalogen will be available for reaction with the metal precursor on allsurfaces (regardless of composition), leading to metal film depositionon all substrate surfaces, including the dielectric surface. In someembodiments, the deposition temperature is at or above the decompositiontemperature of the alkyl halide.

Some embodiments of this disclosure advantageously provide methods forcontrolling the deposition of a metal film. In some embodiments, therate of deposition is controlled. In some embodiments, the location ofdeposition is controlled.

The methods of various embodiments use methods of atomic layerdeposition (ALD) or chemical vapor deposition (CVD) to form the metalfilms. The above disclosure describes an exemplary ALD process withrespect to FIG. 7 and an exemplary CVD process with respect to FIG. 8.

As stated previously, the generalized deposition processes shown inFIGS. 7 and 8 are performed as thermal processes without the use ofplasma reactants. The use and effect of plasmas and other additionalreactants is discussed further below.

Some embodiments of the disclosure advantageously provide methods ofdepositing metal films within substrate features or other structures.Exemplary features or structures include, but are not limited to,trenches and vias.

Some embodiments of the disclosure advantageously provide depositioncontrol methods for reducing film deposition outside of a target featureand near the feature opening. Without being bound by theory, it isbelieved that reducing deposition in these areas allows faster gapfillwithin the target feature and reduces clogging near the feature openingand formation of voids or seams within the feature.

Referring to FIGS. 7 and 8, without limiting the scope of the abovedisclosure, both the ALD and CVD processes described above utilize analkyl halide and a metal precursor to deposit a metal film. Withoutbeing bound by theory, it is believed that the alkyl halide functions asa catalyst in the deposition of the metal film. Accordingly, asparticularly evidenced by the CVD process, a single exposure of thesubstrate surface to an alkyl halide can be used to deposit a thicknessof more than 10 nm of metal film.

Some embodiments of the disclosure advantageously provide depositioncontrol methods for reducing the activity of the catalyst inpredetermined areas of the substrate surface. In some embodiments, theactivity of catalyst is reduced. In some embodiments, the activity ofthe catalyst is eliminated.

Referring to FIGS. 10A-10D, an exemplary substrate 400 is shown duringprocessing according to one or more embodiments of this disclosure. Thesubstrate 1000 illustrated in FIGS. 10A-10D is simplified forexplanation. As mentioned above, and shown in FIG. 9, in someembodiments, the substrates of this disclosure contain features orstructures not depicted in FIGS. 10A-10D.

In FIG. 10A, the substrate 1000 contains a substrate surface 1010. InFIG. 4B, the substrate surface 1010 is exposed to an alkyl halide toform an activated surface 1020. As described above, the alkyl halide1040 adsorbs to the substrate surface 1010 to form an activatedsubstrate surface 1020.

In FIG. 10C, a predetermined area of the activated surface 1020 isexposed to a deactivation treatment to form a deactivated surface 1030.The alkyl halide 1040 shown in FIGS. 10B and 10C is shown as circular orovoid, however no specific molecular shape is intended to be conveyed.Similarly, the difference between the circular shapes shown in FIGS. 10Band 10C and the ovoid shapes shown in FIG. 10C is meant only to conveythe activity and/or relative concentration of alkyl halide on thesubstrate surfaces.

In FIG. 10D, the substrate 1000 is exposed to a metal precursor to forma metal film 1050. As shown in FIG. 10D, the thickness T₁ of the metalfilm 1050 on the activated surface 1020 is greater than the thickness T₂of the metal film 1050 on the deactivated surface 1030.

In some embodiments, the deactivation treatment reduces theconcentration of the alkyl halide on the activated surface 1020. In someembodiments, the deactivation treatment reduces the catalytic activityof the alkyl halide on the activated surface 1020.

In some embodiments, the method described above with respect to FIGS.10A-10D is modified to include the deactivation treatment beforeexposure to the alkyl halide. In this regard, the deactivation treatmentmay be understood to “superactivate” a predetermined area of thesubstrate surface 1010 before exposure to the alkyl halide. Uponexposure to the alkyl halide, the “superactivated” surface forms ahigher concentration or activity of alkyl halide than a surface notexposed to the deactivation treatment. The difference in concentrationand/or activity between the surfaces may be used to control deposition.In some embodiments, the surfaces may be further deactivated asdescribed above with respect to FIGS. 10C-10D.

The thickness T₁ is greater than the thickness T₂. Accordingly, someembodiments of the disclosure advantageously provide deposition controlmethods for controlling the amount of deposition in predetermined areasof the substrate surface.

In some embodiments, the ratio of T₁:T₂ is greater than or equal toabout 1:1, greater than or equal to about 2:1, greater than or equal toabout 3:1, greater than or equal to about 4:1, greater than or equal toabout 5:1, or greater than or equal to about 10:1. In some embodiments,little to no deposition of metal occurs on the deactivated surface 1030.Stated differently, in some embodiments, thickness T₂ is about 0. Stateddifferently, the amount of metal film 1050 deposited on the deactivatedsurface 1030 is essentially none. As used in this regard, “essentiallynone” means that the metal film on the deactivated surface covers lessthan 5%, less than 2%, less than 1% or less than 0.5% of the deactivatedsurface.

The thicknesses of the metal film 1050 deposited on the activatedsurface 1020 and the deactivated surface 1030 is directly proportionalto the rates of deposition on the activated surface 1020 and thedeactivated surface 1030. Accordingly, some embodiments of thedisclosure advantageously provide deposition control methods forcontrolling the rate of deposition in predetermined areas of thesubstrate surface.

In some embodiments, the entire substrate surface is exposed to thedeactivation treatment. Some embodiments of the disclosure may be usedto control the amount of deposition on the entire substrate. Someembodiments of the disclosure may be used to control the rate ofdeposition on the entire substrate.

In some embodiments, not shown, the substrate 1000 comprises one or morefeatures. In some embodiments, the deactivated surface 1030 is thesurface outside of the one or more feature. In some embodiments, thedeactivated surface 1030 is the surface near the top of the sidewall ofthe one or more feature.

Without being bound by theory, it is believed that the surface nearsubstrate features and the top surfaces of the sidewalls of thosefeatures are more highly activated (exhibits greater deposition) due tomultiple exposed faces within close proximity. The greater deposition onthese surfaces increases the likelihood that the feature will closebefore a sufficient amount of film is formed inside of the feature. Whenfeatures close a seam or void is often formed. Accordingly, in someembodiments, the deactivated surface 1030 is the surface near the top ofthe one or more feature. Further, in some embodiments, the deactivatedsurface 1030 is the surface near the substrate feature. In someembodiments, the metal film deposited within the feature has reducedseams or voids. In some embodiments, the metal film deposited within thefeature has substantially no seam or voids. As used in this regard, theterm “substantially no seam” means that any gap formed in the filmbetween the sidewalls is less than about 1% of the cross-sectional areaof the sidewall.

In some embodiments, the predetermined areas of the substrate areexposed to hydrogen gas without the use of plasma.

In some embodiments, a hydrogen gas pulse is introduced into the ALDdeposition cycle described above. Stated differently, a substrate may beexposed to a pulse sequence of alkyl halide, purge, hydrogen gas, purge,metal precursor, purge. In some embodiments, the substrate is exposed toan additional pulse of hydrogen gas followed by a purge after exposureto the metal precursor. In some embodiments, the substrate is exposed toan additional pulse of hydrogen gas followed by a purge after exposureto the alkyl halide. In some embodiments, the purge phase between eachexposure to the metal precursor and/or the alkyl halide is performed insome, but not all cycles.

In some embodiments a hydrogen gas exposure is introduced into the CVDdeposition cycle described above. Stated differently, a substrate may besoaked with the alkyl halide, exposed to hydrogen gas and exposed to themetal precursor. In some embodiments, the substrate is exposed to thehydrogen gas before exposure to the metal precursor. In someembodiments, the hydrogen gas and the metal precursor are flowedsimultaneously.

In some embodiments, the predetermined areas of the substrate areexposed to a plasma comprising one or more of hydrogen (H₂), ammonia(NH₃) or argon (Ar). In some embodiments, the plasma used to deactivatethe surface is a low powered plasma. In some embodiments, the plasma hasa power in a range of about 50 W to about 500 W, in a range of about 50W to about 300W, in a range of about 50 W to about 200 W, or in a rangeof about 50 W to about 100 W.

In some embodiments, the plasma exposure time is less than or equal toabout 30 seconds, less than or equal to about 20 seconds, less than orequal to about 15 seconds, less than or equal to about 10 seconds, lessthan or equal to about 5 seconds, or less than or equal to about 2seconds.

In some embodiments, the plasma is a conductively coupled plasma (CCP).In some embodiments, the plasma is an inductively coupled plasma (ICP).In some embodiments, the plasma is a direct plasma generated within theprocessing environment. In some embodiments, the plasma is a remoteplasma generated outside of the processing environment.

In some embodiments, a plasma pulse is introduced into the ALDdeposition cycle described above. In some embodiments, the plasma pulsereplaces the hydrogen gas pulse described above with respect to the ALDdeposition cycle.

In some embodiments, a plasma pulse is introduced into the CVDdeposition cycle described above. In some embodiments, the plasma pulsereplaces the hydrogen gas exposure described above with respect to theCVD deposition cycle.

Reference throughout this specification to “one embodiment,” “certainembodiments,” “one or more embodiments” or “an embodiment” means that aparticular feature, structure, material, or characteristic described inconnection with the embodiment is included in at least one embodiment ofthe disclosure. Thus, the appearances of the phrases such as “in one ormore embodiments,” “in certain embodiments,” “in one embodiment” or “inan embodiment” in various places throughout this specification are notnecessarily referring to the same embodiment of the disclosure.Furthermore, the particular features, structures, materials, orcharacteristics may be combined in any suitable manner in one or moreembodiments.

Although the disclosure herein has been described with reference toparticular embodiments, it is to be understood that these embodimentsare merely illustrative of the principles and applications of thepresent disclosure. It will be apparent to those skilled in the art thatvarious modifications and variations can be made to the method andapparatus of the present disclosure without departing from the spiritand scope of the disclosure. Thus, it is intended that the presentdisclosure include modifications and variations that are within thescope of the appended claims and their equivalents.

What is claimed is:
 1. A metal deposition method comprising sequentiallyexposing a substrate to a metal precursor and an alkyl halide while thesubstrate is maintained at a deposition temperature to form a metalfilm, the metal precursor having a decomposition temperature above thedeposition temperature, and the alkyl halide comprising carbon andhalogen, and the halogen comprising bromine or iodine.
 2. The method ofclaim 1, wherein the metal is selected from molybdenum, ruthenium,cobalt, copper, platinum, nickel or tungsten.
 3. The method of claim 1,wherein the metal precursor comprises a metal atom bonded to one or moreof an optionally alkyl substituted benzene ring and an open or closeddiene.
 4. The method of claim 1, wherein the alkyl halide consistsessentially of iodoethane or diiodomethane.
 5. The method of claim 1,wherein exposing the substrate to the metal precursor and the alkylhalide comprises a cycle, and the metal film is deposited at a rate ofgreater than or equal to about 0.2 Å/cycle.
 6. The method of claim 1,wherein the metal film has a surface roughness of less than or equal toabout 10% of a thickness of the metal film.
 7. The method of claim 1,wherein the metal film has a carbon content less than or equal to about2% carbon on an atomic basis.
 8. The method of claim 1, wherein themetal film has a purity of greater than or equal to about 97% metal. 9.The method of claim 1, wherein the halogen is insoluble in the metalfilm.
 10. A metal deposition method comprising: exposing a substrate ata deposition temperature to an alkyl halide (R—X) to adsorb R and X onthe substrate; desorbing R in the form of R—R or R; exposing thesubstrate to a metal precursor (M—L); reacting M—L with the adsorbed Xto form M—X; and reacting M—X with M—X to form M—M, herein M—L isthermally stable at the deposition temperature, X is insoluble within M,the bond strength of M—L is less than M—X is less than M—M, and thedeposited metal has a purity of greater than or equal to about 97% metalon an atomic basis.
 11. The method of claim 10, wherein R—X is thermallystable at the deposition temperature.
 12. A method of selectivelydepositing a first metal film on a second metal surface, the methodcomprising: providing a substrate with a first dielectric surface and asecond metal surface; and sequentially exposing the substrate to a firstmetal precursor and an alkyl halide while the substrate is maintained ata deposition temperature, the alkyl halide comprising carbon and halogenatoms, the halogen atoms comprising bromine or iodine, and both themetal precursor and the alkyl halide having a decomposition temperatureabove the deposition temperature.
 13. The method of claim 12, whereinthe first metal is selected from molybdenum, ruthenium or tungsten. 14.The method of claim 12, wherein the first metal precursor comprises ametal atom bonded to one or more of an optionally alkyl substitutedbenzene ring and an open or closed diene.
 15. The method of claim 12,wherein the halogen is insoluble in the metal film.
 16. The method ofclaim 12, wherein the alkyl halide consists essentially of iodoethane.17. The method of claim 12, wherein exposing the substrate to the metalprecursor and the alkyl halide comprises a cycle, and the metal film isdeposited at a rate of greater than or equal to about 0.2 Å/cycle. 18.The method of claim 12, wherein the metal film has a surface roughnessof less than or equal to about 10% of thickness.
 19. The method of claim12, wherein the metal film has a carbon content less than 2% carbon onan atomic basis.
 20. The method of claim 12, wherein the metal film hasa purity of greater than or equal to about 97% metal.